Myosin V is the best characterized vesicle transporter in vertebrates, but it has been unknown as to whether all members of the myosin V family share a common, evolutionarily conserved mechanism of action. We showed that myosin V from Drosophila has a strikingly different motor mechanism from that of vertebrate myosin Va and it is a non-processive, ensemble motor. We are now interested in what role myosin V plays in Drosophila. To do this, we have been localizing myosin V in various stages of development. Preliminary results suggest that myosin V in some cell types localizes to the nucleur envelope where it may interact with lamin B. We are in the process of raising new antibodies and are studying the localization of lamin B in myosin V deficient mutant Drosophila.